U.S. patent application number 15/281525 was filed with the patent office on 2018-04-05 for non-crimp fabric and method of manufacturing.
The applicant listed for this patent is The Boeing Company. Invention is credited to Amol Ogale.
Application Number | 20180093446 15/281525 |
Document ID | / |
Family ID | 61757608 |
Filed Date | 2018-04-05 |
United States Patent
Application |
20180093446 |
Kind Code |
A1 |
Ogale; Amol |
April 5, 2018 |
NON-CRIMP FABRIC AND METHOD OF MANUFACTURING
Abstract
A non-crimp fabric includes a non-crimp layup of one or more
non-crimp layers, each one of the non-crimp layers is formed of
tows arranged parallel to each other, a nonwoven fabric that
includes a nonwoven fabric layer engaged to an outer non-crimp
layer of the non-crimp layup, the nonwoven fabric layer is formed
of fibers, wherein a portion of the fibers extend at least
partially though the non-crimp layup to hold the non-crimp layers
and the nonwoven fabric layer together.
Inventors: |
Ogale; Amol; (Munich,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Boeing Company |
Chicago |
IL |
US |
|
|
Family ID: |
61757608 |
Appl. No.: |
15/281525 |
Filed: |
September 30, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B32B 5/12 20130101; B32B
2307/732 20130101; D04H 3/04 20130101; B32B 2260/023 20130101; B32B
2307/72 20130101; B32B 2262/0269 20130101; D04H 1/4374 20130101;
B32B 2605/18 20130101; B32B 2262/101 20130101; B32B 2262/106
20130101; B32B 2262/10 20130101; B32B 2260/046 20130101; B32B
2262/0253 20130101; B32B 5/06 20130101; B32B 2307/718 20130101;
D04H 1/498 20130101; B32B 2262/02 20130101; B32B 2262/0261
20130101; B32B 2262/0292 20130101; B32B 2262/0276 20130101; D10B
2505/12 20130101; B32B 5/26 20130101; B32B 5/022 20130101 |
International
Class: |
B32B 5/06 20060101
B32B005/06; B32B 5/02 20060101 B32B005/02; B32B 5/12 20060101
B32B005/12; B32B 5/26 20060101 B32B005/26; D04H 1/498 20060101
D04H001/498 |
Claims
1. A non-crimp fabric comprising: a non-crimp layup of one or more
non-crimp layers, each one of said one or more non-crimp layers is
formed of tows arranged parallel to each other; and a nonwoven
fabric integrated through said non-crimp layup to hold said one or
more non-crimp layers and said nonwoven fabric together.
2. The non-crimp fabric of claim 1 wherein said nonwoven fabric
comprises a nonwoven fabric layer engaged to an outer non-crimp
layer of said non-crimp layup, said nonwoven fabric layer is formed
of fibers, and wherein a portion of said fibers are at least
partially integrated through said non-crimp layup to hold said
non-crimp layers and said nonwoven fabric layer together.
3. The non-crimp fabric of claim 2 wherein up to 25 percent of said
fibers of said nonwoven fabric layer are integrated through said
non-crimp layup.
4. The non-crimp fabric of claim 2 wherein said nonwoven fabric
further comprises discontinuous fibers intralayer entangled
together to form a fiber network, and wherein a portion of said
discontinuous fibers extend at least partially through said
non-crimp layup and are interlayer entangled with said tows to hold
said one or more non-crimp layers and said nonwoven fabric layer
together and maintain said tows as substantially non-crimped.
5. The non-crimp fabric of claim 4 wherein said nonwoven fabric
further comprises continuous fibers intralayer entangled together
with said discontinuous fibers to form said fiber network, and
wherein a portion of said continuous fibers extend at least
partially through said non-crimp layup and are interlayer entangled
with said tows to hold said one or more non-crimp layers and said
nonwoven fabric layer together and maintain said tows as
substantially non-crimped.
6. The non-crimp fabric of claim 2 wherein said fibers are needle
punched through said non-crimp layup.
7. The non-crimp fabric of claim 2 wherein each one of said tows
comprises an untwisted bundle of continuous filaments.
8. The non-crimp fabric of claim 7 wherein said filaments comprise
a reinforcement material and wherein said fibers comprise a fiber
material.
9. The non-crimp fabric of claim 8 wherein: said reinforcement
material comprises one of carbon, glass, aramid and
ultra-high-molecular-weight polyethylene, and said fiber material
comprises one of carbon, glass, aramid and
ultra-high-molecular-weight polyethylene
10. The non-crimp fabric of claim 2 wherein said nonwoven fabric is
between approximately 30 percent and approximately 70 percent by
weight of said non-crimp fabric.
11. The non-crimp fabric of claim 2 wherein said non-crimp layup
comprises at least said non-crimp layers, and wherein two or more
of said non-crimp layers of said non-crimp layup are
multi-axial.
12. The non-crimp fabric of claim 1 further comprising a matrix
material at least partially infused through said one or more
non-crimp layers and said nonwoven fabric.
13. A composite structure comprising: one or more reinforcement
layers of a non-crimp fabric, wherein each of said one or more
reinforcement layers of said non-crimp fabric comprises: a
non-crimp layup of one or more non-crimp layers; and a nonwoven
fabric integrated through said non-crimp layup to hold said one or
more non-crimp layers and said nonwoven fabric together; and a
matrix material infused through said reinforcement layers.
14. The composite structure of claim 13 wherein: each one of said
non-crimp layers is formed of tows arranged parallel to each other,
said nonwoven fabric comprises a nonwoven fabric layer engaged to
an outer non-crimp layer of said non-crimp layup, said nonwoven
fabric layer is formed of fibers, and a portion of said fibers
extend at least partially through said non-crimp layup to hold said
non-crimp layers and said nonwoven fabric layer together.
15. The composite structure of claim 14 wherein said nonwoven
fabric further comprises discontinuous fibers intralayer entangled
together to form a fiber network, and wherein a portion of said
discontinuous fibers extend at least partially through said
non-crimp layup and are interlayer entangled with said tows to hold
said one or more non-crimp layers and said nonwoven fabric layer
together and maintain said tows as substantially non-crimped.
16. The composite structure of claim 15 wherein said nonwoven
fabric further comprises continuous fibers intralayer entangled
together and with said discontinuous fibers to form said fiber
network, and wherein a portion of said continuous fibers extend at
least partially through said non-crimp layup and are interlayer
entangled with said tows to hold said one or more non-crimp layers
and said nonwoven fabric layer together and maintain said tows as
substantially non-crimped.
17. The composite structure of claim 14 wherein said fibers are
needle punched through said non-crimp layup.
18. A method for making a non-crimp fabric, said method comprising:
forming a non-crimp layup; forming a nonwoven fabric; and
integrating said nonwoven fabric with said non-crimp layup to hold
said non-crimp layup and said nonwoven fabric together.
19. The method of claim 17 wherein: forming said non-crimp layup
comprises forming one or more non-crimp layers, each of said one or
more non-crimp layers is formed of tows arranged parallel to each
other, and forming said nonwoven fabric comprises a forming a
nonwoven fabric layer, said nonwoven fabric layer is formed of
intralayer entangled fibers.
20. The method of claim 19 further comprising: engaging said
nonwoven fabric layer to an outer non-crimp layer of said non-crimp
layup; penetrating at least a portion of said intralayer entangled
fibers at least partially through said non-crimp layup; and holding
said one or more non-crimp layers and said nonwoven fabric layer
together, wherein at least a portion of said intralayer entangled
fibers are interlayer entangled with said tows.
21. The method of claim 20 wherein penetrating at least a portion
of said intralayer entangled fibers at least partially through said
non-crimp layup comprises needle punching said nonwoven fabric
layer through said non-crimp layers.
22. The method of claim 18 further comprising: at least partially
integrating a matrix material within said one or more non-crimp
layers and said nonwoven fabric layer; and partially curing said
matrix material.
Description
FIELD
[0001] The present disclosure is generally related to composites
and, more particularly, to non-crimp fabrics used as reinforcing
layers to form composite laminates and, still more particularly, to
non-crimp fabrics formed from non-crimp layers held together by an
integrated nonwoven fabric layer.
BACKGROUND
[0002] Composite are widely used in a variety of applications as
high-strength and low-weight materials, for example, to replace
metals. As one example, composites are used in increasing
quantities in aerospace applications due to their high
strength-to-weight ratios, corrosion resistance and other favorable
properties.
[0003] Generally, a composite laminate is formed from one or more
layers of reinforcing fibers infused with a matrix material (e.g.,
a resin). As an example, laminates can be formed of multiple layers
or plies of resin pre-impregnated fibers, known as a prepreg.
Alternatively, laminates can also be formed of multiple layers of
dry fibers, known as a preform or dry fiber layup, which are
subsequently infused with a matrix material to create the final
composite part. The reinforcing fibers of a preform are formed by
laying up several reinforcement layers into a stack of a
predetermined thickness. The reinforcing layers may be
unidirectional or, more typically, multiaxial. As used herein, the
term "unidirectional" means that the reinforcing fibers of all of
the reinforcing layers are arranged in a single orientation or
direction. As used herein, the term "multiaxial" means that the
reinforcing fibers of alternating ones of the reinforcement layers
are arranged in different orientations or directions to produce a
reinforcing fabric with optimum strength and stiffness in one or
more directions.
[0004] Additionally, the reinforcing fibers may be a woven fabric
or a non-crimp fabric. As used herein, the term "woven fabric" has
its ordinary meaning as known to those skilled in the art and may
include fabrics where multiple layers of continuous fibers, or
filaments, are interlaced at 0.degree. (e.g., the warp direction)
and 90.degree. (e.g., the weft direction) to form a woven fabric.
As used here, the term "non-crimp fabric" has its ordinary meaning
as known to those skilled in the art and may include fabrics where
multiple layers of continuous fibers, or filaments, are laid upon
each other (e.g., stacked) and transformed into a fabric by
stitching or application of a binder, such that the filaments
remain straight and without a substantial crimp.
[0005] Traditional non-crimp fabrics offer several performance
advantages relative to woven fabrics. Additionally, non-crimp
fabrics may be cheaper to produce and faster to manufacture. The
primary role of the stitching is to hold the layers of the
non-crimp fabric together. Typically, the stitching is formed from
a thin thermoplastic polymer (e.g., polyester) thread or yarn.
[0006] However, the use of stitching and/or a binder introduces
external foreign material into the non-crimp fabric. Introduction
of foreign material into the non-crimp fabric may create problems
in the final composite made using the non-crimp fabric that is held
together with the stitching and/or binder. As an example, as the
thickness (e.g., the number of layers) of the non-crimp fabric
increases, the ability to conform to changes in the shape of the
component being made from the reinforcing fabric (e.g., drapability
of the reinforcing fabric) decreases due to restrictions imposed by
the stitching or the binding material. As another example, the
material used for the stitching may be incompatible with the
infused matrix material. As yet another example, the stitching
process may create permanent holes in the reinforcing fabric that
may create resin rich zones within the reinforcing fabric during
infusion and/or cause localized resin shrinkage.
[0007] Accordingly, those skilled in the art continue with research
and development efforts in the field of composite laminates and,
more particularly, in the field of non-crimp reinforcing
fabrics.
SUMMARY
[0008] In one embodiment, the disclosed non-crimp fabric includes a
non-crimp layup of non-crimp layers, each one of the non-crimp
layers being formed of tows of reinforcement material arranged
parallel to each other, and a nonwoven fabric integrated through
the non-crimp layup to hold the non-crimp layers and the nonwoven
fabric together.
[0009] In another embodiment, the disclosed composite structure
includes non-crimp layers of a non-crimp fabric, wherein each
non-crimp layer of the non-crimp fabric includes a non-crimp layup
of non-crimp layers, and a nonwoven fabric integrated through the
non-crimp layup to hold the non-crimp layers and the nonwoven
fabric together, and a matrix material infused through the
non-crimp layers of the non-crimp fabric to hold the non-crimp
layers together.
[0010] In yet another embodiment, the disclosed method for making a
non-crimp fabric includes the steps of: (1) forming a non-crimp
layup, (2) forming a nonwoven fabric, and integrating the nonwoven
fabric with the non-crimp layup to hold the non-crimp layup and the
non-woven fabric together.
[0011] Other embodiments of the disclosed apparatus and method will
become apparent from the following detailed description, the
accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic block diagram of one embodiment of the
disclosed non-crimp fabric;
[0013] FIG. 2 is a schematic cutaway perspective view of one
embodiment of the non-crimp layup;
[0014] FIG. 3A is a schematic partial cross-sectional view of one
embodiment of the nonwoven fabric;
[0015] FIG. 3B is a schematic partial top plan view of the nonwoven
fabric shown in FIG. 3A;
[0016] FIG. 4A is a schematic partial cross-sectional view of
another embodiment of the nonwoven fabric;
[0017] FIG. 4B is a schematic partial top plan view of the nonwoven
fabric shown in FIG. 4A;
[0018] FIG. 5 is a schematic partial cross-sectional view of
another embodiment of the disclosed non-crimp fabric;
[0019] FIG. 6 is a schematic partial cross-sectional view of yet
another embodiment of the disclosed non-crimp fabric;
[0020] FIG. 7 is a schematic illustration of one embodiment of the
manufacturing apparatus used to make the non-crimp fabric;
[0021] FIG. 8 is a schematic illustration of another embodiment of
the manufacturing apparatus used to make the non-crimp fabric;
[0022] FIG. 9 is a schematic block diagram of one embodiment of the
composite structure made using the disclosed non-crimp fabric;
[0023] FIG. 10 is a schematic cross-sectional view of another
embodiment of the composite structure;
[0024] FIG. 11 is a flow diagram of one embodiment of the disclosed
method for making the non-crimp fabric;
[0025] FIG. 12 is a schematic illustration of an aircraft; and
[0026] FIG. 13 is a schematic block diagram of aircraft production
and service methodology.
DETAILED DESCRIPTION
[0027] The following detailed description refers to the
accompanying drawings, which illustrate specific embodiments and/or
examples described by the disclosure. Other embodiments and/or
examples having different structures and operations do not depart
from the scope of the present disclosure. Like reference numerals
may refer to the same feature, element or component in the
different drawings.
[0028] Illustrative, non-exhaustive embodiments, which may be, but
are not necessarily, claimed, of the subject matter according the
present disclosure are provided below.
[0029] FIG. 1 is a schematic block diagram illustrating one
embodiment of the disclosed non-crimp fabric 100. In the
illustrative embodiment, the non-crimp fabric 100 includes a
non-crimp layup 102 and a nonwoven fabric 124. The nonwoven fabric
124 is disposed on an outer surface of the non-crimp layup 102. The
nonwoven fabric 124 is integrated through the non-crimp layup 102
to hold the non-crimp layup 102 and the nonwoven fabric 124 (e.g.,
the non-crimp fabric 100) together. Thus, as used herein, the term
"non-crimp fabric" includes fabrics where one or more non-crimp
layers 104 of continuous filaments 118 are laid upon each other
(e.g., stacked) and transformed into a fabric by integrating the
nonwoven fabric 124 with the non-crimp layup 102, such that the
continuous filaments 118 remain straight and without a substantial
crimp.
[0030] In the illustrative embodiment, the non-crimp layup 102
includes or is formed from non-crimp layers 104. Each one of the
non-crimp layers 104 includes or is formed from tows 106. As used
herein, the term "tow" has its ordinary meaning as known to those
skilled in the art and may include or is formed from an untwisted
bundle of continuous filaments 118. The tows 106 are made of a
reinforcement material 108. The tows 106 may also be referred to as
multifilament tows or multifilament yarns. As used herein, the term
"filament" has its ordinary meaning as known to those skilled in
the art and may include one or more fibrous materials adapted for
the non-crimp layer 104 for reinforcement of composites. The
continuous filaments 118 are made of the reinforcement material
108.
[0031] In an example embodiment, the tows 106 forming each
non-crimp layer 104 are arranged parallel to each other in a single
orientation or direction. Thus, the orientation or direction of the
non-crimp layer 104 may be defined by the orientation or direction
of the tows 106. As an example, the tows 106 are spread apart and
positioned relative to each other to form a sheet of the continuous
filaments 118 arranged in a single orientation or direction to form
each non-crimp layer 104.
[0032] In the illustrative embodiment, the nonwoven fabric 124
includes or is formed from a nonwoven fabric layer 110, which may
also be referred to as a nonwoven fiber layer. The nonwoven fabric
layer 110 is engaged to an outer non-crimp layer 112 (FIGS. 5 and
6) of the non-crimp layup 102. The nonwoven fabric layer 110
includes or is formed from fibers 114. As used herein, the term
"fiber" has its ordinary meaning as known to those skilled in the
art and may include one or more fibrous materials adapted for the
nonwoven fabric layer 110. A portion of the fibers 114 extend at
least partially through the non-crimp layup 102 to hold the
non-crimp layers 104 and the nonwoven fabric layer 110
together.
[0033] The non-crimp layup 102 may include any number (e.g., a
plurality) of non-crimp layers 104. As an example, the non-crimp
layup 102 may include two or more non-crimp layers 104 arranged in
a single orientation or direction to form a unidirectional
non-crimp layup 102 and, thus, a unidirectional non-crimp fabric
100. As another example, the non-crimp layup 102 may include two or
more non-crimp layers 104 arranged in different orientations or
directions to form a multiaxial non-crimp layup 102 and, thus, a
multiaxial non-crimp fabric 100.
[0034] In a specific example, the non-crimp layup 102 includes two
non-crimp layers 104 to form a biaxial non-crimp fabric (NCF). In
another specific example, the non-crimp layup 102 includes three
non-crimp layers 104 to form a triaxial (NCF). In yet another
specific example, the non-crimp layup 102 includes four non-crimp
layers 104 to form a quadraxial (NCF). In other examples, the
non-crimp layup 102 includes more than four non-crimp layers
104.
[0035] FIG. 2 is a schematic cutaway view of one embodiment of the
non-crimp layup 102. The non-crimp layup 102 is constructed from a
stack or laminate of superimposed non-crimp layers 104. The
non-crimp layers 104 may also referred to as plies or lamina. In
the illustrative embodiment, the non-crimp layup 102 includes five
non-crimp layers 104, identified as a first non-crimp layer 104A, a
second non-crimp layer 104B, a third non-crimp layer 104C, a fourth
non-crimp layer 104D and a fifth non-crimp layer 104E.
[0036] The reinforcing tows 106 of the superimposed non-crimp
layers 104 form an angle relative to each other when viewed
perpendicular to the layer plane. The orientation or direction of
the tows 106 forming each of the non-crimp layers 104 alternates in
several different directions to produce the multiaxial non-crimp
layup 102, for example, having optimum strength and stiffness in
one or more of the different directions. By this configuration it
is possible to carry out an adaptation of the direction of the
reinforcing tows 106 with respect to the directions of stress in a
subsequent composite structure or component, for example, the
composite structure 200 (FIG. 9), and to ensure the required
strengths in these directions of stress.
[0037] In the illustrative embodiment, the non-crimp layers 104 are
superimposed such that the reinforcing tows 106 of the non-crimp
layers 104 are oriented parallel to each other or alternately
crosswise. When the non-crimp layers 104 of reinforcing tows 106
alternate at defined angles with respect to the zero-degree
direction, a symmetrical or quasi-isotropic structure results. The
numbers of non-crimp layers 104 and the layup angles are virtually
infinitely adjustable. Typically, for multiaxial non-crimp fabrics
122, angles of 0.degree., 90.degree., plus or minus 20.degree.,
plus or minus 25.degree., plus or minus 30.degree., plus or minus
45.degree., plus or minus 60.degree., or plus or minus 80.degree.
are set and the structure is selected such that a symmetrical
structure with respect to the zero-degree direction results. As
illustrated in FIG. 2, in a specific example, the non-crimp layers
104 are multi-axial with the tows 106 of respective non-crimp
layers 104A-104E being arranged at angles of 0.degree., 90.degree.,
+45.degree., 90.degree. and -45.degree., respectively.
[0038] The present disclosure recognizes that arranging the
reinforcing tows 106 parallel to each other and abutting parallel
together within each non-crimp layer 104 provides high filament
volume proportions and avoids zones with low filament proportions,
which is advantageous with respect to providing a high level of the
mechanical characteristics in the resulting composite structure
(e.g., composite structure 200).
[0039] In an exemplary embodiment, the reinforcing tows 106 are
carbon tows. In other words, the reinforcement material 108 (FIG.
1) is carbon and the continuous filaments 118 (FIG. 1) forming the
multifilament reinforcing tows 106 are continuous carbon filaments
(e.g., carbon fiber filaments). As used herein, the term
"continuous filament" has its ordinary meaning as known to those
skilled in the art and may include a long filament, also commonly
referred to as an elongated fiber, that extends across
substantially the entire length or width of an associated non-crimp
layer 104 or the non-crimp layup 102.
[0040] In another example embodiment, the reinforcing tows 106 are
glass tows, for example, the reinforcement material 108 (FIG. 1) is
glass and the continuous filaments 118 (FIG. 1) forming the
multifilament tows 106 are continuous glass filaments (e.g., glass
fiber filaments). In another example embodiment, the reinforcing
tows 106 are aramid tows, for example, the reinforcement material
108 is an aramid and the continuous filaments 118 forming the
multifilament tows 106 are continuous aramid filaments (e.g.,
aramid fiber filaments). In yet another example embodiment, the
reinforcing tows 106 are ultra-high-molecular-weight (UHMW)
polyethylene tows, for example, the reinforcement material 108 is
UHMW polyethylene and the continuous filaments 118 forming the
multifilament tows 106 are continuous UHMW polyethylene filaments
(e.g., aramid fiber filaments).
[0041] FIG. 3A is a schematic partial cross-sectional view of one
embodiment of the nonwoven fabric 124. FIG. 3B is a schematic
partial top plan view of the nonwoven fabric 124 of FIG. 3A. FIG.
4A is a schematic partial cross-sectional view of another
embodiment of the nonwoven fabric 124. FIG. 4B is a schematic
partial top plan view of the nonwoven fabric 124 of FIG. 4A. In the
illustrative embodiments, the nonwoven fabric layer 110 includes or
is formed by a three-dimensional network or web of intralayer
entangled fibers 114, generally referred to herein as a fiber
network 120. As used herein, the term "intralayer entangled" has
its ordinary meaning as known to those skilled in the art and may
include fibers 114 that are mechanically entwined and interlocked
with other fibers 114 within the fiber network 120 forming the
nonwoven fabric layer 110.
[0042] In various embodiments, the nonwoven fabric layer 110 may be
implemented as at least one of a nonwoven veil, mat, sheet, tape or
some other type of collection of fibers 114 formed with a nonwoven
configuration, such as a fabric that is spunbonded, spunlaced or
mesh fabric.
[0043] In the illustrative embodiment shown in FIGS. 3A and 3B, the
fiber network 120 includes or is formed from discontinuous fibers
114A. As used herein, the term "discontinuous fiber" has its
ordinary meaning as known to those skilled in the art and may
include a relatively short fiber 114 (e.g., thread-like structures)
that does not extend across substantially the entire length or
width of the nonwoven fabric layer 110. In an example
implementation, the discontinuous fibers 114A may have a minimum
length substantially equal to the combined thickness T.sub.1 of the
non-crimp layup 102 (e.g., the stacked non-crimp layers 104) and
thickness T.sub.2 of the nonwoven fabric layer 110 (FIGS. 5 and 6).
As an example, the majority (e.g., between approximately 50 percent
and approximately 90 percent) of the discontinuous fibers 114A have
a length of between approximately 10 mm and 100 mm.
[0044] As an example, the fiber network 120 may include a plurality
of intermingled and intralayer entangled discontinuous fibers 114A
dispersed into a non-woven format. As an example, the intralayer
entangled discontinuous fibers 114A are mechanically entwined and
interlocked with other discontinuous fibers 114A within the fiber
network 120 forming the nonwoven fabric layer 110. As a specific
example, the discontinuous fibers 114A may be formed from chopped
continuous filaments, such as recycled continuous filaments.
[0045] As an example, the discontinuous fibers 114A may include
relatively short fibers of at least one of the same sizes, same
diameters, same cross-sectional shapes, same types, or some
combination thereof. As another example, the discontinuous fibers
114A may include relatively short fibers of at least one of
different sizes, different diameters, different cross-sectional
shapes, different types, or some combination thereof.
[0046] In the illustrative embodiment shown in FIGS. 4A and 4B, the
fiber network 120 includes or is formed from discontinuous fibers
114A and continuous fiber 114B. As used herein, the term
"continuous fiber" has its ordinary meaning as known to those
skilled in the art and may include a relatively long fiber 114 that
extends across one of substantially the entire length or width of
the nonwoven fabric layer 110. As an example, the continuous fibers
114B may include a length of less than approximately 1 m up to the
length of the nonwoven fabric 124.
[0047] As an example, the fiber network 120 may include a plurality
of intermingled and intralayer entangled discontinuous fibers 114A
and continuous fibers 114B dispersed into a non-woven format. As an
example, the intralayer entangled continuous fibers 114B are
mechanically entwined and interlocked with other continuous fibers
114B and discontinuous fibers 114A within the fiber network 120
forming the nonwoven fabric layer 110. As an example, the
continuous fibers 114B may be formed from recycled continuous
filaments.
[0048] As an example, the continuous fibers 114B may include
relatively long fibers of at least one of the same sizes, same
diameters, same cross-sectional shapes, same types, or some
combination thereof. As another example, the continuous fibers 114B
may include relatively long fibers of at least one of different
sizes, different diameters, different cross-sectional shapes,
different types, or some combination thereof.
[0049] In the illustrative embodiments, the fibers 114 (e.g., the
discontinuous fibers 114A or the discontinuous fibers 114A and the
continuous fibers 114B) have a random orientation relative to each
other. However, in other embodiments, the fibers 114 may not be
randomly oriented relative to each other.
[0050] In the illustrative embodiments, the fiber network 120 also
includes openings 126 formed between the fibers 114, for example,
the discontinuous fibers 114A of the example configuration shown in
FIGS. 3A and 3B and the discontinuous fibers 114A and continuous
fibers 114B of the example configuration shown in FIGS. 4A and 4B.
In the illustrative embodiments, the density of fibers 114 of the
fiber network 120 is sufficiently low such that a porosity of the
nonwoven fabric layer 110 is above a selected threshold. The
selected threshold may be selected such that the permeability of
the nonwoven fabric layer 110, for example, with respect to a
resin, is below a selected threshold. As an example, the nonwoven
fabric layer 110 may have a density of approximately 20 g/m.sup.2
at a thickness T.sub.2 of approximately 0.5 mm. As another example,
the nonwoven fabric layer 110 may have a density of approximately
400 g/m.sup.2 at a thickness T.sub.2 of between approximately 2 mm
and approximately 10 mm.
[0051] As used herein, the term "porosity" has its ordinary meaning
as known to those skilled in the art and may include the measure of
how much open space is present within the item. For example and
without limitation, the open space may be in the form of the
openings 126 or voids, gaps, or some other type of open space. As
used herein, the term "permeability" has its ordinary meaning as
known to those skilled in the art and may include the measure of
the ease with which a fluid, such as a resin, can move through the
item. Typically, increased porosity results in increased
permeability. In an exemplary embodiment, the fiber network 120 may
have a permeability sufficiently high to allow resin to permeate,
or flow through, the nonwoven fabric layer 110, for example, when a
resin system or other matrix material is infused or integrated
within non-crimp fabric 100 when making a composite structure, such
as the disclosed composite structure 200 (FIG. 9).
[0052] In the illustrative embodiments, the fiber network 120
includes a sufficient number of fibers 114 to create a sufficient
number of crossover points 128 between intersecting fibers 114 to
provide sufficient entanglement of the fibers 114 and hold the
fiber network 120 together, thereby forming a stable nonwoven
fabric 124 (e.g., nonwoven fabric layer 110). As used herein, the
term "stable" has its ordinary meaning as known to those skilled in
the art and may include a fiber network 120 that is sufficiently
strong, due to the entanglement of the fibers 114, to not fall
apart or tear during formation of the disclosed non-crimp fabric
100. The present disclosure recognizes that the use of
discontinuous fibers 114A and continuous fiber 114B may increase
the stability of the fiber network 120 by providing an increased
number of crossover points 128 between the fibers 114 without
increasing the density and weight of the nonwoven fabric layer
110.
[0053] The fibers 114 (e.g., the discontinuous fibers 114A or the
discontinuous fibers 114A and the continuous fibers 114B) of the
fiber network 120 forming the nonwoven fabric layer 110 are made of
fiber material 116 (FIG. 1). In an example embodiment, the fiber
material 116 of the discontinuous fibers 114A and/or the continuous
fibers 114B is the same. In such an example embodiment, the fiber
network 120 forms a homogeneous nonwoven fabric layer 110. In
another example, the fiber material 116 of the discontinuous fibers
114A and the continuous fibers 114B is different. In such an
example embodiment, the fiber network 120 forms a heterogeneous
nonwoven fabric layer 110.
[0054] In an example embodiment, the fiber material 116 of the
fibers 114 (e.g., the discontinuous fibers 114A or the
discontinuous fibers 114A and the continuous fibers 114B) of the
fiber network 120 forming the nonwoven fabric layer 110 of the
nonwoven fabric 124 and the reinforcement material 108 (FIG. 1) of
the reinforcing tows 106 (e.g., the continuous filaments 118)
forming the non-crimp layers 104 of the non-crimp layup 102 (FIG.
1) are the same. In such an example embodiment, the non-crimp layup
102 (e.g., the non-crimp layers 104) and the nonwoven fabric 124
(e.g., the nonwoven fabric layer 110) form a homogeneous non-crimp
fabric 100.
[0055] As such, in an exemplary embodiment, the fiber material 116
is carbon. In other words, the fibers 114 (e.g., the discontinuous
fibers 114A or the discontinuous fibers 114A and the continuous
fibers 114B) are carbon fibers. In another embodiment, the fiber
material 116 is glass, for example, the fibers 114 (e.g., the
discontinuous fibers 114A or the discontinuous fibers 114A and the
continuous fibers 114B) are glass fibers. In another embodiment,
the fiber material 116 is an aramid, for example, the fibers 114
(e.g., the discontinuous fibers 114A or the discontinuous fibers
114A and the continuous fibers 114B) are aramid fibers. In yet
another embodiment, the fiber material 116 is UHMW polyethylene,
for example, the fibers 114 (e.g., the discontinuous fibers 114A or
the discontinuous fibers 114A and the continuous fibers 114B) are
UHMW polyethylene fibers.
[0056] In another example embodiment, the fiber material 116 of the
fibers 114 (e.g., the discontinuous fibers 114A or the
discontinuous fibers 114A and the continuous fibers 114B) and the
reinforcement material 108 of the reinforcing tows 106 are
different. In such an example embodiment, the non-crimp layup 102
and the nonwoven fabric 124 form a heterogeneous non-crimp fabric
100.
[0057] As examples, the fiber material 116 may include at least one
of silica (e.g., silica fibers), polyamide (e.g., polyamide
fibers), polyether ketone (PEK) (e.g., PEK fibers), polyester
(e.g., polyester fibers), polyether sulfone (PES) (e.g., PES
fibers), polyimide (e.g., polyimide fibers), polyurethane (e.g.,
polyurethane fibers) or other types of fibers.
[0058] The fiber network 120 forming the nonwoven fabric layer 110
may include individual strands of fiber material 116 (e.g.,
individual fibers 114) and/or bundles of strands of fiber material
116 (e.g., bundles of fibers 114). In an exemplary embodiment of
the fiber network 120, the fibers 114 (e.g., strands of fiber
material 116 or bundles of fiber material 116) are sufficiently
intermingled and entwined, have a sufficient number of crossover
points 128 and/or have sufficient entanglement to produce a stable
nonwoven fabric layer 110 without the need for a binder or other
additional additive. Alternatively, in another example embodiment,
the fiber network 120 may include an additional binder (not
explicitly illustrated), such as dry thermoplastic fibers or powder
or wet polymer solutions or emulsions, applied to the fibers 114 to
produce the nonwoven fabric layer 110. In this example embodiment,
the additional binder may add further features or material
characteristics to the nonwoven fabric layer 110, such as
pre-compaction of the nonwoven fabric layer 110, for example,
following heat treatment.
[0059] FIG. 5 is a schematic partial cross-sectional view of one
embodiment of the disclosed non-crimp fabric 100. In the
illustrative embodiment, the nonwoven fabric layer 110 is
positioned or disposed in contact with the outermost (e.g., top or
bottom) non-crimp layer 112 of the non-crimp layup 102. At least of
portion of the fibers 114 (e.g., discontinuous fibers 114A or
discontinuous fibers 114A and continuous fibers 114B) (FIG. 1)
extend at least partially though the thickness T of the non-crimp
layup 102. The fibers 114 of the nonwoven fabric layer 110
integrate themselves within one or more non-crimp layers 104 of the
non-crimp layup 102 in order to hold the non-crimp layers 104
together and to hold the nonwoven fabric layer 110 and the
non-crimp layup 102 together. The fibers 114 are intermingled and
are interlayer entangled with the reinforcing tows 106. As used
herein, the term "interlayer entangled" has its ordinary meaning as
known to those skilled in the art and may include may include
fibers 114 (e.g., discontinuous fibers 114A or discontinuous fibers
114A and continuous fibers 114B) that are mechanically entwined and
interlocked with the continuous filaments 118 of the reinforcing
tows 106 forming the non-crimp fabric 100. In other words, the
nonwoven fabric 124 serves as the holding material to hold the
layers of the multiaxial non-crimp layup 102 together without the
use of polymer stitches or a binding material.
[0060] In the illustrative example, tufts 130 of fibers 114 extend
from the nonwoven fabric layer 110 through the outermost non-crimp
layer 112 (e.g., non-crimp layer 104A, as illustrated in FIG. 5)
and into one or more of the other non-crimp layers 104 (e.g.,
non-crimp layers 104B-104E, as illustrated in FIG. 5). Each tuft
130 may include any number of fibers 114. The fibers 114 of the
nonwoven fabric layer 110 intermingle and entangle with the tows
106 (e.g., the continuous filaments 118) (FIG. 1) of each non-crimp
layer 104 of the non-crimp layup 102 in order to hold the non-crimp
layers 104 together and to hold the nonwoven fabric layer 110 and
the non-crimp layup 102 together.
[0061] Therefore, the superimposed non-crimp layers 104 are
connected and secured to each other via a plurality of the tufts
130 of fibers 114 running through the thickness T of the non-crimp
layup 102, such that the tows 106 (e.g., the continuous filaments
1118) remain straight and without a substantial crimp and the
(e.g., unidirectional or multiaxial) non-crimp fabric 100 is
stabilized.
[0062] FIG. 6 is a schematic partial cross-sectional view of
another embodiment of the disclosed non-crimp fabric 100. In the
illustrative embodiment, the nonwoven fabric layer 110 is
positioned or disposed in contact with both of the outermost (e.g.,
top and bottom) non-crimp layers 112 of the non-crimp layup 102
(e.g., non-crimp layer 104A and non-crimp layer 104E, as
illustrated in FIG. 6). At least of portion of the fibers 114
(e.g., discontinuous fibers 114A or discontinuous fibers 114A and
continuous fibers 114B), such as in the form of tufts 130 of fibers
114, from each one of the nonwoven fabric layers 110 extend at
least partially though the thickness T of the non-crimp layup 102.
The fibers 114 of the nonwoven fabric layers 110 integrate
themselves within one or more non-crimp layers 104 of the non-crimp
layup 102 in order to hold the non-crimp layers 104 together and to
hold the nonwoven fabric layers 110 and the non-crimp layup 102
together.
[0063] In an exemplary embodiment, the density of fibers 114
forming the fiber network 120 of the nonwoven fabric layer 110 is
sufficient to achieve an optimum number of fibers 114 extending
through and entangling with the non-crimp layers 104.
[0064] In an exemplary embodiment, the density of fibers 114
forming the fiber network 120 in the nonwoven fabric layer 110 is
lower than the density of continuous filaments 118 of the
reinforcing tows 106 forming the non-crimp layers 104.
[0065] In various example embodiments, the ratio by weight of the
nonwoven fabric layer 110 to the non-crimp layers 104 (e.g., fibers
114 to filaments 118) may vary widely, for example, depending upon
the configuration of the nonwoven fabric layer 110 and/or the one
or more non-crimp layers 104, the intended use of the disclosed
non-crimp fabric 100, for example, as a dry preform or a wet
preform and the like. In an exemplary implementation, the ratio by
weight of the nonwoven fabric layer 110 to the non-crimp layers 104
may be approximately 70:30. As an example configuration of this
implementation, the non-crimp fabric 100 may includes one
unidirectional non-crimp layer 104. In another exemplary
implementation, the ratio by weight of the nonwoven fabric layer
110 to the non-crimp layers 104 may be approximately 30:70. As an
example configuration of this implementation, the non-crimp fabric
100 includes a plurality of multiaxial non-crimp layers 104. In
another example implementation, the ratio by weight of the nonwoven
fabric layer 110 to the non-crimp layers 104 may be between
approximately 25:75 and approximately 75:25. In yet another example
implementation, the ratio by weight of the nonwoven fabric layer
110 to the non-crimp layers 104 may be as much as approximately
5:95 to approximately 95:5.
[0066] In an exemplary embodiment, the portion of the fibers 114
(e.g., discontinuous fibers 114A or discontinuous fibers 114A and
continuous fibers 114B) that extend, that penetrate and/or that are
integrated at least partially through the non-crimp layup 102 may
be between approximately 1 percent and approximately 25 percent of
the fibers 114 forming the nonwoven fabric layer 110.
[0067] FIG. 7 is a schematic illustration of one embodiment of the
disclosed apparatus 300 for making the disclosed non-crimp fabric
100. In the illustrative embodiment, the apparatus 300 includes a
lay-up device 302 configured to form the non-crimp layup 102. The
apparatus 300 also includes a needle punch device 304 configured to
embed the fibers 114 (FIG. 1) of the nonwoven fabric 124 through
the non-crimp layup 102.
[0068] The lay-up device 302 is configured to construct the
non-crimp layup 102 by forming each one of the non-crimp layers 104
from reinforcing tows 106 and superimposing the non-crimp layer 104
at defined angles with respect to the zero-degree direction to form
the non-crimp layup 102. As an example, the reinforcing tows 106
may be provided to the lay-up device 302. As an example, the tows
106 may be drawn from a tow supply reel 306 or take-off roll. The
lay-up device 302 positions the tows 106 within the non-crimp
layers 104 with respect to each other such that they are
substantially parallel to each other and abut each other,
essentially adjacent to each other without any substantial gaps.
The lay-up device 302 provides for X-axis and Y-axis orientation of
the tows 106 in order to form a multiaxial non-crimp layup 102.
[0069] In an example implementation, each one of the non-crimp
layers 104 of the non-crimp layup 102 may be successively placed on
and supported by the nonwoven fabric 124 forming the nonwoven
fabric layer 110. In another example implementation, the non-crimp
layup 102 may be completely formed and placed on the nonwoven
fabric layer 110. Once the lay-up device 302 forms the non-crimp
layup 102, the apparatus 300 is configured to superimpose the
nonwoven fabric 124 and the non-crimp layup 102. As an example, one
or more guide rollers 308 positions the nonwoven fabric layer 110
into surface contact with the non-crimp layup 102. As an example,
the nonwoven fabric 124 may be drawn from a nonwoven fabric supply
reel 310 or take-off roll.
[0070] The nonwoven fabric 124 may be introduced to the non-crimp
layup 102 in an unconsolidated state or in a partially consolidated
state. As used herein, the term "unconsolidated" has its ordinary
meaning as known to those skilled in the art and may include the
nonwoven fabric 124 being in a fluffy or uncompressed condition or
form, for example, having a density of approximately 400 g/m.sup.2
with a thickness of approximately 10 mm. As used herein, the term
"consolidated" has its ordinary meaning as known to those skilled
in the art and may include the nonwoven fabric 124 being in a
compressed condition or form, for example, having a density of
approximately 400 g/m.sup.2 with a thickness of approximately 2 mm.
As used herein, the term "partially consolidated" has its ordinary
meaning as known to those skilled in the art and may include the
nonwoven fabric 124 being compressed, but not compressed into a
final consolidated form. Consolidation may be achieved by some
combination of heat and/or pressure.
[0071] The superimposed nonwoven fabric layer 110 and non-crimp
layup 102 is then passed to the needle punch device 304. The needle
punch device 304 may also be referred to as a needle loom. The
needle punch device 304 includes a needle board 312, configured to
be reciprocated vertically (e.g., moves up and down) by any
suitable reciprocating mechanism 314 (e.g., a crankshaft). The
needle board 312 includes or carries a plurality of coarse gauge
barbed needles 316.
[0072] The barbed needles 316 are passed or driven through aligned
holes in a plate 318, through the superimposed nonwoven fabric
layer 110 and non-crimp layup 102 (e.g., the plurality of non-crimp
layers 104), and through aligned holes in a bed plate 320, and are
then withdrawn. During passage of the barbed needles 316 through
the nonwoven fabric layer 110, the barbs engage certain ones of the
fibers 114 of the nonwoven fabric layer 110 and carry them at least
partially or substantially entirely through the non-crimp layup 102
where they entangle and intermingle with the tows 106 (e.g., the
continuous filaments 118) of one or more of the non-crimp layers
104. When the barbed needles 316 are withdrawn, the fibers 114 are
released from the barbs and remain as the tufts 130 of fibers 114
penetrated through the non-crimp layup 102 and intermingled and
interlayer entangled with the reinforcing tows 106 to form the
non-crimp fabric 100. The needle punch device 304 may partially
consolidate the nonwoven fabric layer 110.
[0073] Those skilled in the art will appreciate that the size, or
gauge, of the barbed needles 316 may be determined and/or selected
according to various material and/or process parameters and/or
needs, such as the size (e.g., cross-sectional dimension or
diameter) of the fibers 114, the size (e.g., cross-sectional
dimension or diameter) of the filaments 118, the friction produced
between the needles 316 and the fibers 114 and filaments 118, the
processing speed of the superimposed nonwoven fabric layer 110 and
non-crimp layup 102 through the needle punch device 304, the
processing speed of the needle board 312 through the superimposed
nonwoven fabric layer 110 and non-crimp layup 102, the overall
thickness of the superimposed nonwoven fabric layer 110 and
non-crimp layup 102 (e.g., the combined thickness T.sub.1 and
T.sub.2) (FIGS. 5 and 6).
[0074] Following integration of the nonwoven fabric layer 110 and
the non-crimp layup 102 by the needle punch device 304, the
non-crimp fabric 100 is passed through at least one pair of
pressure rollers 322 to completely consolidate the nonwoven fabric
layer 110 and compress (e.g., calender) the non-crimp fabric 100 to
a final thickness, for example, approximately 0.2 mm.
[0075] The final non-crimp fabric 100 may then be stored on a
non-crimp fabric reel 324 or take-in roll.
[0076] FIG. 8 is a schematic illustration of another embodiment of
the disclosed apparatus 300 for making the disclosed non-crimp
fabric 100. In the illustrative embodiment, the apparatus 300
includes the lay-up device 302 configured to form the non-crimp
layup 102 and a pair of needle punch devices 304 configured to
embed the fibers 114 (FIG. 1) of two nonwoven fabrics 124 through
the non-crimp layup 102.
[0077] Once the lay-up device 302 forms the non-crimp layup 102,
the apparatus 300 is configured to superimpose two nonwoven fabrics
124 and the non-crimp layup 102. As an example, one or more guide
rollers 308 positions two nonwoven fabric layers 110 into opposing
surface contact with the non-crimp layup 102.
[0078] The superimposed nonwoven fabric layers 110 and non-crimp
layup 102 is then consecutively passed to the needle punch devices
304 where the barbed needles 316 pass through the nonwoven fabric
layer 110, engage certain ones of the fibers 114 of an associated
one of the nonwoven fabric layers 110 and carry them at least
partially or substantially entirely through the non-crimp layup 102
where they entangle and intermingle with the tows 106 (e.g., the
continuous filaments 118) of one or more of the non-crimp layers
104.
[0079] In the illustrative embodiment, the apparatus 300 may also
include a spreading device 326 configured to spread a binding
material 328 over at least one surface of the non-crimp fabric 100.
The binding material 328 may be used to bind multiple layers of
non-crimp fabric 100 together, for example, when making the
disclosed composite structure 200.
[0080] The resulting non-crimp fabric 100 may be used to make
structural components, such as a composite structure 200 (FIGS. 9
and 10).
[0081] FIG. 9 is a schematic block diagram of one embodiment of the
disclosed composite structure 200. FIG. 10 is a schematic
cross-sectional view of another embodiment of the disclosed
composite structure 200. In the illustrative embodiment, the
composite structure 200 takes the form of a composite laminate 202.
The composite laminate 202 includes or is formed of one or more
composite layers 208, also referred to as plies or lamina. The
composite layers 208 (e.g., each one of the composite layers 208)
include or are formed of one or more reinforcement layers 122 and a
matrix material 204. The reinforcement layers 122 (e.g., each one
of the reinforcement layers 122) include or are formed of one or
more layers of the non-crimp fabric 100. As also illustrated in
FIG. 1, the non-crimp fabric 100 includes or is formed of the
nonwoven fabric layer 110 integrated through the non-crimp layup
102 of one or more non-crimp layers 104.
[0082] Referring to FIGS. 9 and 10, and with reference to FIGS.
1-6, as such, in the illustrative embodiments, the composite
structure 200 (FIGS. 9 and 10) includes or is formed from the
non-crimp fabric 100 (e.g., FIGS. 1, 5 and 6), which is formed from
the nonwoven fabric layer 110 (e.g., FIGS. 3A, 3B, 4A and 4C)
integrated through the non-crimp layup 102 (e.g., FIGS. 1 and 2) to
stabilize and hold the non-crimp fabric 100 together, which is then
integrated or infused with the matrix material 204. As described
herein above, the non-crimp fabric 100 takes the form of the
non-crimp layup 102 held together by the integrated nonwoven fabric
layer 110. The non-crimp layup 102 may be formed of the non-crimp
layers 104 formed of the tows 106 (e.g., FIGS. 1 and 2). The
nonwoven fabric layer 110 may take the form of the nonwoven fabric
124 formed of fibers 114 (e.g., FIGS. 3A, 3B, 4A and 4C). The
non-crimp layers 104 of the non-crimp fabric 100 may be oriented in
a single direction to make the composite layers 208 unidirectional
or in two or more directions to make the composite layers 208
multi-axial.
[0083] Referring to FIG. 9, as an example, the matrix material 204
may take the form of a resin 206. As used herein the terms "matrix
material" and "resin" have their ordinary meaning as known to those
skilled in the art and may refer to the resin composition or resin
system in the structural composite layer 208, and, optionally, may
include minor amounts of additives.
[0084] The resin 206 may include at least one polymer. As examples,
the resin 206 may be a polymeric resin including at least one of a
thermosetting polymer, a thermoplastic polymer, or some other type
of polymer, an epoxy-based resin and the like. Optionally, the
matrix material 204 may also toughened by adding particles of a
thermoplastic material to the resin 206.
[0085] Referring to FIGS. 9 and 10, during production of the
composite structure 200, one or more layers of the non-crimp fabric
100, used as the reinforcement layers 122, may be cut to shape and
draped over a pre-form tool (not explicitly illustrated) to produce
a three-dimensional shape of the composite structure 200. Thus, the
non-crimp fabric 100 may also be referred to as a preform.
[0086] In an example implementation of production of the composite
structure 200, the disclosed non-crimp fabric 100, for example,
made using the apparatus 300 (FIGS. 7 and 8) in accordance with the
disclosed method 500 (FIG. 11), is a dry preform, i.e., with no
matrix material 204 present. One or more layers of the dry preform
(e.g., the non-crimp fabric 100 used as the reinforcement layers
122) are laid up to form the desired (e.g., three-dimensional)
shape of the composite structure 200. The composite structure 200
is then formed by integrating or infusing the matrix material 204
within and through the laid up (e.g., stacked) dry preforms and
fully curing matrix material 204.
[0087] In another example implementation of production of the
composite structure 200, following formation of the disclosed
non-crimp fabric 100, for example, made using the apparatus 300
(FIGS. 7 and 8) in accordance with the disclosed method 500 (FIG.
11), the non-crimp fabric 100 may be subsequently partially
integrated or infused with the matrix material 204 and partially
cured to become a wet preform, also known as a prepreg. One or more
layers of the wet preform (e.g., the non-crimp fabric 100 used as
the reinforcement layers 122 infused with the matrix material 204)
are laid up to form the desired (e.g., three-dimensional) shape of
the composite structure 200. The composite structure 200 is then
formed by fully curing the matrix material 204 of the laid up
(e.g., stacked) wet preforms.
[0088] As used herein, the terms "integrating," "infusing,"
"integrated," "infused" and similar terms have their ordinary
meaning as known to those skilled in the art and may include
causing the matrix material 204 (e.g., the resin 206) to be located
within the reinforcement layer 112 (e.g., the non-crimp fabric
100). This integration may be performed by, for example and without
limitation, infusing the non-crimp fabric 100 with the resin 206,
injecting the resin 206 into non-crimp fabric 100, saturating the
non-crimp fabric 100 with the resin 206, mixing the resin 206 with
the non-crimp fabric 100, impregnating the non-crimp fabric 100
with the resin 206, or some combination thereof.
[0089] The composite structure 200 may then be left uncured,
partially cured, or fully cured, depending on the implementation.
This composite structure 200 may be referred to as an integrated
preform. When left uncured, the composite structure 200 may be
referred to as an integrated preform or an uncured composite
structure. The integrated preform may be partially cured to take
the form of a partially cured composite structure. This partial
curing may be performed to allow easier transport and handling of
the composite structure. The integrated preform may be fully cured
to take the form of a fully cured composite structure. A carbon
fiber-reinforced polymer (CFRP) laminate is an example of one type
of the composite laminate 202.
[0090] FIG. 11 is a flow diagram of one embodiment of the disclosed
method 500 for making a non-crimp fabric, for example, to be used
in production of a composite structure. The method 500 illustrated
in FIG. 11 may be implemented to form the disclosed non-crimp
fabric 100 (FIG. 1), which may be used to make the disclosed
composite structure 200 (FIG. 9).
[0091] As shown at block 502, the non-crimp layup 102 is formed. As
shown at block 504, the non-crimp layup 102 is formed by laying up
the non-crimp layers 104. As used herein, the terms "layup" and
"laying up" have their ordinary meaning as known to those skilled
in the art and may include one or more non-crimp layers 104 that
are placed adjacent one another. Each of the non-crimp layers 104
is formed of tows 106 arranged parallel to each other.
[0092] As shown at block 506, the nonwoven fabric 124 is formed. As
shown at block 508, the nonwoven fabric 124 is formed by forming a
nonwoven fabric layer 110 of intralayer entangled fibers 114.
[0093] As shown at block 510, the nonwoven fabric layer 110 is
engaged to the outer non-crimp layer 112 of the non-crimp layup
102.
[0094] As shown at block 512, the non-crimp layup 102 and the
nonwoven fabric 124 are integrated to hold the non-crimp layup 102
and the nonwoven fabric 124 (e.g., non-crimp fabric 100) together
in order to make the non-crimp fabric 100. As shown at block 514,
at least a portion of the fibers 114 (e.g., the intralayer
entangled fibers 114) are penetrated at least partially through the
non-crimp layup 102. As shown at block 516, the nonwoven fabric
layer 110 is needle punched through the non-crimp layers 104 to
penetrate the fibers 114 through the non-crimp layup 102. As shown
at block 518, the one or more non-crimp layers 104 and the nonwoven
fabric layer 110 are held together by the fibers 114 extending
through the non-crimp layup 102. At least a portion of the
intralayer entangled fibers 114 of the nonwoven fabric layer 110
are interlayer entangled with the tows 118 of the one or more
non-crimp layers 104 to hold the non-crimp layers 104 and the
nonwoven fabric layer 110 together and form the non-crimp fabric
100.
[0095] As discussed above, the preceding steps of the disclosed
method 500 illustrated by example in blocks 502, 504, 508, 510,
512, 514, 516 and 518 may produce the non-crimp fabric 100 free of
the matrix material 204, otherwise known as the dry preform, which
may then be used to produce the disclosed composite structure 200
(FIGS. 9 and 10).
[0096] Optionally, the disclosed method 500 may include additional
steps to produce the non-crimp fabric 100 that is pre-impregnated
with the matrix material 204, otherwise known as the wet preform or
pregreg. As such in an example embodiment, the method 500 may be
implemented to make a pre-impregnated non-crimp fabric 100, which
may then be used to make the disclosed composite structure 200
(FIGS. 9 and 10).
[0097] As shown at block 520, the matrix material 204 is at least
partially integrated or infused through the one or more non-crimp
layers 104 (e.g., the non-crimp layup 102) and the nonwoven fabric
layer 110 held together by the intralayer entangled fibers 114 of
the nonwoven fabric layer 110 being interlayer entangled with the
tows 118 of the one or more non-crimp layers 104. As shown at block
522, the matrix material 204 is partially cured to make the
pre-impregnated non-crimp fabric 100.
[0098] In an exemplary implementation of the disclosed method 500,
the manufacturing apparatus 300 (FIGS. 7 and 8) may be used to make
the non-crimp fabric 100.
[0099] Based on its specific structure, the disclosed non-crimp
fabric 100 distinguishes itself by a good drapability and
fixability of the non-crimp layers 104 in the preform, by a good
permeability during the infiltration with the matrix material 204
and good surface finish of the composite structure 200. The
nonwoven fabric layer 110 also provides additional thickness to the
non-crimp fabric 100 without increasing cost. In addition, the
non-crimp fabric 100 enables the production of composite structures
200 with high mechanical strengths, high stability against
compression loading and high tolerance to impact loading. The
disclosed non-crimp fabric 100 is therefore especially suitable for
the production of preforms, from which more complex fiber composite
components are produced.
[0100] Advantageously, the nonwoven fabric layer 110 stabilizes the
non-crimp layup 102 by holding the non-crimp layers 104 together in
a substantially crimp-free construction, while maintaining the
orientation or direction of the tows 106 forming each non-crimp
layer 104. Thus, the nonwoven fabric layer 110 enables easier
handling of the multiaxial non-crimp fabric 100 since the non-crimp
layup 102 remains intact. Further, straight, non-crimped tows 106
within a reinforcing fabric allows for very good resin impregnation
and wet-out. Further, use of the nonwoven fabric layer 110 to hold
the non-crimp layers 104 together and stabilize the non-crimp layup
102 may eliminate the need for stitching or application of a binder
and the disadvantages associated with their use. The disclosed
non-crimp fabric 100 formed from the nonwoven fabric layer 110
integrated into the non-crimp layers 104 prevents crimping or
undulations in the non-crimp layers 104 that can lead to a loss of
performance in a finished composite laminate.
[0101] Additionally, the non-crimp fabric 100 formed in accordance
with the present disclosure may provide an additional
cost-effective advantage by utilizing recycled carbon fiber or
other reinforcing fibers extracted during the recycling of cured
composite parts. The disclosed non-woven fabric layer 110 may be
formed of continuous 114A and or discontinuous 114B from a recycled
source, which results in a lower cost and environmentally friendly
benefit for the non-woven fabric 124 and for the associated
non-crimp fabric 100.
[0102] Additionally, since the disclosed non-crimp fabric 100 is
formed without the use of stitching or a binder to hold the
non-crimp layers 104 together, which introduces foreign material,
the step of removing such stitching or other foreign material
during a subsequent recycling operation is eliminated. As such, in
various embodiments of the disclosed non-crimp fabric 100, recycled
fibers and/or filaments may be used as the fibers 114 of the
nonwoven fabric layer 110.
[0103] Examples of the disclosed non-crimp fabric 100 and the
composite structure 200 made with the non-crimp fabric 100 and the
methods for making the same disclosed herein may be described in
the context of an aircraft manufacturing and service method 1100 as
shown in FIG. 12 and the aircraft 1200 as shown in FIG. 13.
[0104] During pre-production, the illustrative method 1100 may
include specification and design, as shown at block 1102, of
aircraft 1200 and material procurement, as shown at block 1104.
During production, component and subassembly manufacturing, as
shown at block 1106, and system integration, as shown at block
1108, of the aircraft 1200 may take place. Production of non-crimp
fabric 100 and use of non-crimp fabric 100 in the composite
structure 200, as described herein, may be accomplished as a
portion of the production, component and subassembly manufacturing
step (block 1106) and/or as a portion of the system integration
(block 1108). Thereafter, the aircraft 1200 may go through
certification and delivery, as shown block 1110, to be placed in
service, as shown at block 1112. While in service, the aircraft
1200 may be scheduled for routine maintenance and service, as shown
at block 1114. Routine maintenance and service may include
modification, reconfiguration, refurbishment, etc. of one or more
systems of the aircraft 1200.
[0105] Each of the processes of illustrative method 1100 may be
performed or carried out by a system integrator, a third party,
and/or an operator (e.g., a customer). For the purposes of this
description, a system integrator may include, without limitation,
any number of aircraft manufacturers and major-system
subcontractors; a third party may include, without limitation, any
number of vendors, subcontractors, and suppliers; and an operator
may be an airline, leasing company, military entity, service
organization, and so on.
[0106] As shown in FIG. 13, the aircraft 1200 produced by the
illustrative method 1100 may include an airframe 1202, for example,
having composite panels or other composite structures including the
non-crimp fabric 100, a plurality of high-level systems 1204 and an
interior 1206. Examples of the high-level systems 1204 include one
or more of a propulsion system 1208, an electrical system 1210, a
hydraulic system 1212 and an environmental system 1214. Any number
of other systems may be included. Although an aerospace example is
shown, the principles disclosed herein may be applied to other
industries, such as the automotive industry, the marine industry,
and the like.
[0107] The systems, apparatus and methods shown or described herein
may be employed during any one or more of the stages of the
manufacturing and service method 1100. For example, components or
subassemblies corresponding to component and subassembly
manufacturing (block 1106) may be fabricated or manufactured in a
manner similar to components or subassemblies produced while the
aircraft 1200 is in service (block 1112). Also, one or more
examples of the systems, apparatus, and methods, or combination
thereof may be utilized during production stages (blocks 1108 and
1110). Similarly, one or more examples of the systems, apparatus,
and methods, or a combination thereof, may be utilized, for example
and without limitation, while the aircraft 1200 is in service
(block 1112) and during maintenance and service stage (block
1114).
[0108] Reference herein to "embodiment" means that one or more
feature, structure, element, component or characteristic described
in connection with the embodiment is included in at least one
implementation of the disclosed invention. Thus, the phrase "one
embodiment," "another embodiment," and similar language throughout
the present disclosure may, but do not necessarily, refer to the
same embodiment. Further, the subject matter characterizing any one
embodiment may, but does not necessarily, include the subject
matter characterizing any other embodiment.
[0109] Similarly, reference herein to "example" means that one or
more feature, structure, element, component or characteristic
described in connection with the example is included in at least
one embodiment. Thus, the phrases "one example," "another example,"
and similar language throughout the present disclosure may, but do
not necessarily, refer to the same example. Further, the subject
matter characterizing any one example may, but does not
necessarily, include the subject matter characterizing any other
example.
[0110] Unless otherwise indicated, the terms "first," "second,"
etc. are used herein merely as labels, and are not intended to
impose ordinal, positional, or hierarchical requirements on the
items to which these terms refer. Moreover, reference to a "second"
item does not require or preclude the existence of lower-numbered
item (e.g., a "first" item) and/or a higher-numbered item (e.g., a
"third" item).
[0111] As used herein, the phrase "at least one of", when used with
a list of items, means different combinations of one or more of the
listed items may be used and only one of the items in the list may
be needed. The item may be a particular object, thing, or category.
In other words, "at least one of" means any combination of items or
number of items may be used from the list, but not all of the items
in the list may be required. For example, "at least one of item A,
item B, and item C" may mean item A; item A and item B; item B;
item A, item B, and item C; or item B and item C. In some cases,
"at least one of item A, item B, and item C" may mean, for example
and without limitation, two of item A, one of item B, and ten of
item C; four of item B and seven of item C; or some other suitable
combination.
[0112] As used herein, the terms "approximately" and "about"
represent an amount close to the stated amount that still performs
the desired function or achieves the desired result. For example,
the terms "approximately" and "about" may refer to an amount that
is within less than 10% of, within less than 5% of, within less
than 1% of, within less than 0.1% of, and within less than 0.01% of
the stated amount.
[0113] As used herein, the term "substantially" may include exactly
and similar, which is to an extent that it may be perceived as
being exact. For illustration purposes only and not as a limiting
example, the term "substantially" may be quantified as a variance
of +/-5% from the exact or actual. For example, the phrase "A is
substantially the same as B" may encompass embodiments where A is
exactly the same as B, or where A may be within a variance of
+/-5%, for example of a value, of B, or vice versa.
[0114] As used herein, the terms "partially" or "at least a portion
of" may represent an amount of a whole that includes an amount of
the whole that may include the whole. For example, the term "a
portion of" may refer to an amount that is greater than 0.01% of,
greater than 0.1% of, greater than 1% of, greater than 10% of,
greater than 20% of, greater than 30% of, greater than 40% of,
greater than 50% of, greater than 60%, greater than 70% of, greater
than 80% of, greater than 90% of, greater than 95% of, greater than
99% of, and 100% of the whole.
[0115] In FIGS. 1, 9 and 13, referred to above, solid lines, if
any, connecting various elements and/or components represent
mechanical, electrical, fluid, optical, electromagnetic and other
couplings and/or combinations thereof. As used herein, "coupled"
means associated directly as well as indirectly. For example, a
member A may be directly associated with a member B, or may be
indirectly associated therewith, e.g., via another member C. It
will be understood that not all relationships among the various
disclosed elements are necessarily represented. Accordingly,
couplings other than those depicted in the block diagrams may also
exist. Dashed lines, if any, connecting blocks designating the
various elements and/or components represent couplings similar in
function and purpose to those represented by solid lines; however,
couplings represented by the dashed lines are either selectively
provided or relate to alternative examples of the present
disclosure. Likewise, elements and/or components, if any,
represented with dashed lines, indicate alternative examples of the
present disclosure. One or more elements shown in solid and/or
dashed lines may be omitted from a particular example without
departing from the scope of the present disclosure. Environmental
elements, if any, are represented with dotted lines. Virtual
(imaginary) elements may also be shown for clarity. Those skilled
in the art will appreciate that some of the features illustrated in
FIGS. 1, 9 and 13 may be combined in various ways without the need
to include other features described in FIGS. 1, 9 and 13, other
drawing figures, and/or the accompanying disclosure, even though
such combination or combinations are not explicitly illustrated
herein. Similarly, additional features not limited to the examples
presented, may be combined with some or all of the features shown
and described herein.
[0116] In FIGS. 11 and 12, referred to above, the blocks may
represent operations and/or portions thereof and lines connecting
the various blocks do not imply any particular order or dependency
of the operations or portions thereof. Blocks, if any, represented
by dashed lines indicate alternative operations and/or portions
thereof. Dashed lines, if any, connecting the various blocks
represent alternative dependencies of the operations or portions
thereof. It will be understood that not all dependencies among the
various disclosed operations are necessarily represented. FIGS. 11
and 12 and the accompanying disclosure describing the operations of
the disclosed methods set forth herein should not be interpreted as
necessarily determining a sequence in which the operations are to
be performed. Rather, although one illustrative order is indicated,
it is to be understood that the sequence of the operations may be
modified when appropriate. Accordingly, modifications, additions
and/or omissions may be made to the operations illustrated and
certain operations may be performed in a different order or
simultaneously. Additionally, those skilled in the art will
appreciate that not all operations described need be performed.
[0117] Although various embodiments of the disclosed apparatus,
systems and methods have been shown and described, modifications
may occur to those skilled in the art upon reading the
specification. The present application includes such modifications
and is limited only by the scope of the claims.
* * * * *